The Montreal-based visual effects studio Modus FX served as the lead facility for Duncan Jones' upcoming action thriller Source Code, scheduled for release on April 1. Source Code tells the story of a U.S. soldier who wakes up in the body of another man and discovers he's part of a mission to find the bomber of a Chicago commuter train - forced to relive the final 8 minutes of the incident over and over again until he finds the perpetrator. This December, Modus FX delivered over 150 shots for the film, including complex digital crowd shots, CG trains, environments and dramatic pyrotechnics.

"It's been an absolute pleasure to work with Modus, and it has been a huge eye opener, revealing just what high levels of work are possible from the best of boutique postproduction houses in the world," said Jones, whose feature film directorial debut, 2009's Moon won awards and critical acclaim around the world.

As lead facility on the project, Modus FX worked with a group of five other companies - Rodeo FX, Fly Studio, Mr. X, Oblique FX and MPC Vancouver - in completing a total of 158 shots. Of these, 98 shots were completed in-house at Modus. The facility also created the assets for the other post houses, coordinating the entire process, so everyone would be able to meet their deliveries. "Source Code is the most ambitious and the most challenging project that we've tackled so far," said Yanick Wilisky, VP of production and VFX supervisor at Modus. "It was a very exciting and satisfying project to be involved in."

Wilisky explained that Modus had been brought on board early in pre-production to provide pre-visualization for the film. "We started doing the previs for the main action scenes - how the train would explode, and where this would take place - so we were responsible for the feel and pacing of the key effects sequence."

Among other scenes, the artists at Modus FX created the fictional "Glenbrook Station" in Chicago and its surroundings in CG, including everything from CG trees to large crowds of people and commuter traffic on the busy Chicago streets.

The crowd shots were created using Massive Software's Academy Award(r)-winning 3D crowd behavior system. Massive was also used for aerial shots of cars. "We needed to craft some pretty big highway traffic scenes with about 6,000 cars. That's a lot to render, when you count the number of polygons per car," Wilisky added. "All of the trains are also CG, so we needed to create photo-real close-up shots every time the train pulls into the station and commuters pour in and out of the train."

For CG supervisor, Mostafa Badran, those close-up shots were the biggest challenge. "The train is so predominant in all of the shots that it really is a character in its own right," said Badran. "It goes without saying that the train needed to be photorealistic, so we had our work cut out for us. In a fast-paced drama like Source Code, the moment that the audience wonders if that train is real or not, you've failed."

"It's up close and personal, so camera tracking was a challenge at times," he continued. "You have tracking markers, but in a complicated shot you might have 20 people walking in front of them or accidentally displacing them, so there was a fair amount of work to get the cameras matched perfectly."

"Lens distortion proved to be another challenge on the close-up shots, but our pipeline is well-suited to deal with that. We needed to match a CG element to a practical prop on a live plate and make sure that the distortion value was identical on all of the 3D renders. It's kind of ironic when you're using CG to make something less perfect!" Badran laughed. To deal with lens distortion, the company used Science.D.Visions' 3DEqualizer software and a special plug-in from La Maison.

In addition, the shiny steel surfaces of the train were reflective, so artists at Modus had to create reflections and shadows of the station and the characters to mirror the movements of the train and the actors in the CG environment.

Jones was delighted with the results. "Digital effects are fast evolving, and Modus are redefining how and who film makers can rely on to have their visions achieved," he commented. "I would not hesitate to put them at the top of my list for my next film. In fact, I intend to."

Produced by the Mark Gordon Company and Vendome Pictures, Source Code, (a Summit Entertainment Release), stars Jake Gyllenhaal, Michelle Monaghan and Vera Farmiga. The film was directed by Duncan Jones. The visual effects supervisor was Louis Morin. Source Code will premiere at the SXSW Film Festival, March 11-19 in Austin, Texas, and is scheduled for theatrical release on April 1, 2011